/****************************************************************************
 *
 * Copyright 2017 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 * arch/arm/src/tiva/tiva_start.c
 *
 *   Copyright (C) 2009, 2012, 2014 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/config.h>

#include <stdint.h>
#include <assert.h>
#include <debug.h>

#include <tinyara/init.h>
#include <arch/board/board.h>

#include "up_arch.h"
#include "up_internal.h"

#include "tiva_lowputc.h"
#include "tiva_syscontrol.h"
#include "tiva_start.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Data
 ****************************************************************************/

/****************************************************************************
 * Public Data
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: showprogress
 *
 * Description:
 *   Print a character on the UART to show boot status.
 *
 ****************************************************************************/

#ifdef CONFIG_DEBUG
#define showprogress(c) up_lowputc(c)
#else
#define showprogress(c)
#endif

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: _start
 *
 * Description:
 *   This is the reset entry point.
 *
 ****************************************************************************/

void __start(void)
{
#ifdef CONFIG_BOOT_RUNFROMFLASH
	const uint32_t *src;
#endif
	uint32_t *dest;

	/* Configure the UART so that we can get debug output as soon as possible */

#ifdef CONFIG_TIVA_BOARD_EARLYINIT
	board_earlyinit();
#else
	up_clockconfig();
	up_lowsetup();
#endif
	showprogress('A');

	/* Clear .bss.  We'll do this inline (vs. calling memset) just to be
	 * certain that there are no issues with the state of global variables.
	 */

	for (dest = &_sbss; dest < &_ebss;) {
		*dest++ = 0;
	}
	showprogress('B');

#ifdef CONFIG_BOOT_RUNFROMFLASH
	/* Move the initialized data section from his temporary holding spot in
	 * FLASH into the correct place in SRAM.  The correct place in SRAM is
	 * give by _sdata and _edata.  The temporary location is in FLASH at the
	 * end of all of the other read-only data (.text, .rodata) at _eronly.
	 */

	for (src = &_eronly, dest = &_sdata; dest < &_edata;) {
		*dest++ = *src++;
	}
	showprogress('C');
#endif

	/* Perform early serial initialization */

#ifdef USE_EARLYSERIALINIT
	up_earlyserialinit();
#endif
	showprogress('D');

	/* Initialize onboard resources */

	tiva_boardinitialize();
	showprogress('E');

	/* Then start NuttX */

	showprogress('\r');
	showprogress('\n');
	os_start();

	/* Shouldn't get here */

	for (;;) ;
}
